Synthesis of (+)-manoalide via a copper(I)-mediated 1,2-metalate rearrangement

J Org Chem. 2003 May 16;68(10):4008-13. doi: 10.1021/jo0268097.

Abstract

An enantiospecific synthesis of the phospholipase A(2) inhibitor (+)-(4R)-manoalide is reported in which all 25 carbons of the sesterterpenoid skeleton are constructed from 3-furaldehyde, trimethylalane, oxirane, CO, beta-ionone, and propargyl bromide. The overall yield for the longest linear sequence (12 steps) is 12%. Key steps include (a) a zirconium-catalyzed carboalumination reaction to construct the C10-C11 trisubstituted alkene, (b) a Cu(I)-mediated 1,2-metalate rearrangement to construct the C6-C7 trisubstituted alkene, (c) a Sharpless kinetic resolution to secure the (4R)-stereochemistry, (d) generation of a 5-stannyl-2,3-dihydrofuran by Mo-catalyzed cycloisomerization of a homopropargylic alcohol, and (e) construction of the hydroxyfuranone ring by photooxidation of a silylfuran.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkenes / analysis
  • Alkenes / chemical synthesis*
  • Animals
  • Catalysis
  • Copper / chemistry*
  • Cyclization
  • Kinetics
  • Magnetic Resonance Spectroscopy
  • Molecular Structure
  • Oxidation-Reduction
  • Porifera / chemistry
  • Stereoisomerism
  • Terpenes / analysis
  • Terpenes / chemical synthesis*
  • Zirconium / chemistry

Substances

  • Alkenes
  • Terpenes
  • Copper
  • Zirconium
  • manoalide